Department of Veterans Affairs  •   Puget Sound Health Care System  •  American Lake & Seattle

University of Washington Diabetes Research Group

Study Details: Effect of Dietary Glycemic Index on Beta-cell Function

What does the study involve?

  • Screening visit to see if you have impaired glucose tolerance and are eligible to be in the study
  • A nutrition visit and 3 day food record
  • A total of 6 weeks on a research diet: You will pick up your food twice a week during this time and all your food will be provided to you. The first 2 weeks will be a control diet and the remaining 4 weeks will be either a low glycemic index or a high glycemic index diet. Your weight will be kept stable while on the diets. If you are assigned to the high glycemic index diet, you will be asked to take either NAC or placebo capsules twice a day.
  • Study procedures will occur at the end of the control diet and again at the end of the low or high glycemic index diets. Study procedures involve having IVs for blood sampling and infusion of glucose and insulin, checking your blood glucose with a glucometer for 3 days and wearing a special continuous glucose monitoring system for 3 days. There are a total of 4 study procedure visits.

Who is eligible?

You may be eligible if you have impaired glucose tolerance. Impaired glucose tolerance is a condition where the glucose levels (blood sugar) two hours after drinking a special glucose drink are elevated above normal (140-200 mg/dl), but are not in the diabetes range. We will test for this at the screening visit by doing an oral glucose tolerance test.

You may be at risk for impaired glucose tolerance if any of the following apply.

  • You are overweight and someone in your family has diabetes
  • You had diabetes when you were pregnant
  • Your doctor told you that your fasting glucose level was high or you had borderline diabetes
  • Your A1c (a screening test for diabetes) is between 5.7 and 6.4%
Click here to see if you qualify


Subjects can receive up to $200 for participation

study contact:

For more information about the study, contact:

Kristina Utzschneider, MD 206-277-3568